code: def _get_next_image_index(self):
      if (
          self._reading_index < 0
          or self._reading_index >= self._num_images
      ):
          self._reset_reading_order()
      next_image_index = self._reading_order[self._reading_index]
      self._reading_index += 1
      return next_image_index
  
file_path: CNTK/Examples/Image/Detection/utils/od_reader.py
imports: import zipfile
  import cv2
  import numpy
  import os
  from utils.proposal_helpers import ProposalProvider, compute_targets, compute_image_stats
label_desc: Use image node_id 9 for calling the ObjectDetectionReader obj's underlying member method code with example usage: obj._get_next_image_index() and returns: next_image_index